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Fully suppressing edge-localized modes (ELMs), e.g., with resonant magnetic perturbations (RMPs), is essential to reach and sustain high-performance steady-state H-mode plasmas because large ELMs can significantly reduce the lifetime of divertor components in future tokamak reactors. RMP-driven ELM suppression in KSTAR has been modeled by coupling the neoclassical transport code PENTRC to the nonlinear 3D MHD code JOREK. We have found that the radial transport from the combined effects of the kink-peeling, tearing response, and neoclassical toroidal viscosity can explain the pedestal degradation observed in experiments. In addition, it has been found that the RMP response can increase the inter-ELM heat flux on the lower outer divertor by redistributing the heat transport between the divertor plates. In addition to the degraded pedestal, ELM suppression is also attributable to the RMP-induced mode interactions. While the linear stability of peeling-ballooning mode (PBMs) improves owing to the degraded pedestal, the PBM and RMP interaction increases the spectral transfer between edge harmonics, preventing catastrophic growth and the crash of unstable modes. Here, it turns out that the magnetic islands near the pedestal top can play a vital role in mediating the mode interactions.

The aim of the present study was to investigate the effect of a single nucleotide polymorphism (SNP) of the endothelin receptor B subtype 2 (EDNRB2) gene on plumage coloration in mule ducks. Test mating (white Tsaiya × white Muscovy ducks) in combination with polymerase chain reaction restriction fragment length polymorphism (PCR RFLP) was performed to investigate the effect of non synonymous SNPs in two maternal lines (a conservation and a selection population) on plumage coloration in mule ducks. One non synonymous SNP (c.995G>A) was identified in white Muscovy ducks and white Tsaiya ducks by PCR high resolution melting (PCR HRM) and DNA sequencing. Genotyping results showed that the c.995G>A locus is associated with plumage colour in two maternal populations of white Tsaiya ducks. Further, the maternal genotype of c.995G>A SNP affects the plumage colour of mule ducks. Therefore, the polymorphisms within the EDNRB2 gene at c.995G>A in white Tsaiya ducks may be used in marker assisted selection to improve the plumage colour of mule ducks. Keywords: Muscovy drakes, polymerase chain reaction restriction fragment length, single nucleotide polymorphism, Tsaiya ducks

Toroidal rotation dynamics without any external torque sources in KSTAR ohmic L-mode discharges is investigated. The KSTAR ohmic plasmas mostly flow in the counter-current direction and the toroidal rotation velocity increases as the plasma density rises. The measured radial electric field in T-10 ohmic plasmas is generally negative and its magnitude increases as the density rises (Melnikov et al 2013 Nucl. Fusion 53 093019). A theoretical picture is introduced in this study to explain how the radial electric field and the toroidal rotation change with the same tendency. The radial electric field can be built up to satisfy the ambipolarity condition and ultimately rotate the plasmas in the toroidal direction.

During the COVID-19 pandemic, WHO and CDC suggest people stay 1 m and 1.8 m away from others, respectively. Keeping social distance can avoid close contact and mitigate infection spread. Many researchers suspect that suggested distances are not enough because aerosols can spread up to 7-8 m away. Despite the debate on social distance, these social distances rely on unobstructed respiratory activities such as coughing and sneezing. Differently, in this work, we focused on the most common but less studied aerosol spread from an obstructed cough. The flow dynamics of a cough jet blocked by the backrest and gasper jet in a cabin environment was characterized by the particle image velocimetry (PIV) technique. It was proved that the backrest and the gasper jet can prevent the front passenger from droplet spray in public transportation where maintaining social distance was difficult. A model was developed to describe the cough jet trajectory due to the gasper jet, which matched well with PIV results. It was found that buoyancy and inside droplets almost do not affect the short-range cough jet trajectory. Infection control measures were suggested for public transportation, including using backrest/gasper jet, installing localized exhaust, and surface cleaning of the backrest.

KSTAR has clarified a set of unresolved 3D physics issues utilizing the ITER-like in-vessel, three-row, resonant magnetic perturbation (RMP) configurations. Since RMP-driven, edge-localized-modes (ELMs)-crash control elevates the divertor heat flux peak through its impact on edge plasma parameters and transport, a series of intentionally misaligned RMP configurations (IMCs) have been explored to investigate the relationship between RMP ELM control and divertor heat fluxes, while searching for an ideal IMC that could be favorable in both aspects. First of all, the contrasting influence of kink vs anti-kink phasing on the ELM-crash suppression has been articulated, demonstrating the synergistic benefit of ‘kink’ phasing on ELM-crash-suppression. On the other hand, the three-row IMC in the anti-kink phasing becomes more insensitive to the ELM-crashes at the sub-marginal level of RMP, consistent with theory. Meanwhile, the divertor ‘wetted’ area of ELM-crash-suppression gets narrower than that of ELM-crash-mitigation, suggesting that ELM-crash-mitigation remains advantageous over ELM-crash-suppression in terms of time-averaged divertor thermal loading. In comparison, based on a set of two-row IMCs, no evidence of divertor heat flux broadening was found during ELM-crash-suppression, supporting a hypothesis that the dispersal of the divertor heat flux in three-row IMCs cannot be driven by helically structured two-row RMPs alone. Among ITER-like three-rows, lower two-row RMPs have been found to be much more effective in suppressing the ELM-crashes than upper two-row RMPs. Although it is quite preliminary, the up/down asymmetric dependence of RMP coupling may be generically attributed to lower-single-null plasmas. Such a holistic understanding of RMP-driven, ELM-crash-control in KSTAR is expected not only to elucidate various subtle points in the vicinity of ELM-crash-suppression, but also to clarify the relevant divertor thermal loading issues for ITER and beyond.

Supplemental material, DS_10.1177_2380084420906114 for Patterns in Pediatric Dental Surgery under General Anesthesia across 7 State Medicaid Programs by H.H. Lee, L. Faundez, C. Yarbrough, C.W. Lewis and A.T. LoSasso in JDR Clinical & Translational Research

Few studies have examined the long-term risks of kidney removal to donors despite the increase of frequency in kidney transplantation. This is the 1st study to develop prediction models of chronic kidney disease (CKD) for the 1-year period after donor nephrectomy in living donors. A prospective cohort of patients who underwent donor nephrectomy from March 1, 2006, to December 31, 2016, at the Severance Hospital, Seoul, South Korea, was used. CKD was defined as a glomerular filtration rate (GFR)

Numerous studies have shown that osteoporosis is common in kidney transplant recipients. However, the change in bone mineral density after kidney transplantation (KT) is not fully understood.Thirty-nine kidney transplant recipients with bone densitometry at pretransplant and 24 months after KT were reviewed.The recipients' median age (44.5 ± 10.7 years) and dialysis duration before KT (4.2 ± 3.4 years) were recorded. The T-scores of the lumbar spine and femur neck at 24 months after KT were positively associated with the respective pretransplant T-score (P .001 in the lumbar spine and P .001 in the femur neck). However, the T-score after KT did not show significant change (P = .680 in lumbar spine, P = .093 in femur neck). Changes in the T-scores of the lumbar spine and femur neck over 24 months (delta T-score) were negatively associated with the respective pretransplant T-scores (P = .001 in lumbar spine, P = .026 in femur neck). Changes in the T-scores of the lumbar spine and femur neck over 24 months (delta T-score) were also associated with the pretransplant T-scores after the adjustment of other variables.The change of bone mineral density was related with pretransplant bone mineral density. Careful follow-up of bone densitometry for KT recipients was needed.

Background Many living kidney donors are still at risk of chronic kidney disease (CKD) 1 year after nephrectomy. Although some donors still experience poor renal function, many exhibit delayed recovery of renal function afterwards. We studied the factors related to delayed recovery of renal function in patients with CKD at 1 year after nephrectomy. Methods Patients who underwent donor nephrectomy from March 2006 to April 2014 with a follow-up creatinine study at 1 month, 6 months, 1 year, and after 3 years of follow-up were included in the study. Age, sex, history of hypertension or diabetes, body mass index, blood pressure, complete blood cell count, preoperative routine serum chemistry, and urine study results were reviewed. Results Among 275 donors, 83 (30.2%) who had an estimated glomerular filtration rate (eGFR) 5 mL/min/1.73 m2 were included in the recovery group (n = 48 [57.8%]), and those who did not were included in the nonrecovery group (n = 35 [42.2%]). The preoperative and 1-year follow-up eGFR did not differ significantly between the 2 groups, and the maximum eGFR after 3 years was higher in the recovery group (68.68 mL/min/1.73 m2 [IQR, 61.81–75.64 mL/min/1.73 m2] vs 55.63 mL/min/1.73 m2 [IQR, 51.73–58.29 mL/min/1.73 m2]; P Conclusions Although 30.2% of donors had CKD at 1 year after nephrectomy, 57.8% reported improved renal function. Those with a history of hypertension and high preoperative uric acid levels were less likely to have improvements in renal function and required close follow-up.

This study assesses the association between abdominal aortic calcification (AAC) and renal function of living kidney donors and evaluate AAC as a surrogate marker for nephrosclerosis.Between January 2010 and March 2013, 287 donors who underwent living donor nephrectomy were enrolled. We analyzed computed tomography angiographies and quantified AAC scores by calculating the Agatston score for the abdominal aorta. The donors were stratified into the non-AAC group (AAC score = 0; n = 238) and the AAC group (AAC score0; n = 49). The relationship between AAC and perioperative estimated glomerular filtration rate was analyzed. For the 180 donors consenting to implantation biopsy, the nephrosclerosis score was defined as the sum of abnormalities, including glomerulosclerosis, tubular atrophy, interstitial fibrosis, and arteriosclerosis.The mean AAC score was 185.5 ± 263.3 in the AAC group. The AAC group was older than the non-AAC group (51.1 ± 6.1 vs 37.9 ± 11 years; P .001). Perioperative renal function was not different between the 2 groups. However, among the AAC group, donors with an AAC score of100 were associated with delayed renal function recovery (P = .035). Donors with AAC were more likely to have glomerulosclerosis (50.0% vs 29.1%; P = .022), tubular atrophy (62.5% vs 33.1%; P = .002), and a higher nephrosclerosis score (P = .002).Living donors with an AAC score of100 require close observation because they have a higher probability of delayed renal function recovery after donation. AAC is associated with nephrosclerosis in healthy adults.

Cerebral ischemia is one of the leading causes of morbidity and mortality worldwide. Although stroke (a form of cerebral ischemia)-related costs are expected to reach 240.67 billion dollars by 2030, options for treatment against cerebral ischemia/stroke are limited. All therapies except anti-thrombolytics (i.e., tissue plasminogen activator) and hypothermia have failed to reduce neuronal injury, neurological deficits, and mortality rates following cerebral ischemia, which suggests that development of novel therapies against stroke/cerebral ischemia are urgently needed. Here, we discuss the possible mechanism(s) underlying cerebral ischemia-induced brain injury, as well as current and future novel therapies (i.e., growth factors, nicotinamide adenine dinucleotide, melatonin, resveratrol, protein kinase C isozymes, pifithrin, hypothermia, fatty acids, sympathoplegic drugs, and stem cells) as it relates to cerebral ischemia.

Besides the initial description of IgG4-related pancreatic disease, other sites are now commonly involved. However, occurrence of IgG4-related disease is rare in organ transplanted patients. A 57-year-old man who received a kidney transplantation presented with recurrent dyspnea on exertion. A computed tomography scan of the chest revealed bilateral interlobular septal thickening and multiple tubular and branching small nodular lesions in the right upper lobe, and mass-like consolidation of the left middle lobe. Despite no elevation of serum IgG4 level, a percutaneous core needle biopsy on consolidative mass showed interstitial fibrosis and infiltration of IgG4-positive plasma cells to be more than > 20 per high power field. After treatment with glucocorticoids and rituximab, the consolidative mass of the left middle lobe disappeared.

Smoking is known to result in a decline in renal allograft function and survival of recipients; however, the effect of smoking on living kidney donors remains unknown. In this study we evaluated the impact of cigarette smoking on renal function of kidney donors.Among 1056 donors who underwent nephrectomy, 612 completed the 6-month follow-up protocol and were enrolled in the study. The association of smoking status, including pack-years smoking history, and postoperative renal function was evaluated.Among donors, 68.1% had never smoked, 8% were former smokers, and 23.9% were current smokers. Donors who never smoked were older than former and current smokers (42.3 ± 11.8, 41.9 ± 11.1, and 38.3 ± 10.9 years, respectively; P .001). There was no difference in preoperative renal function between groups; however, postoperative estimated glomerular filtration rate (eGFR) was lower in former and current smokers than in those who never smoked (64.6 ± 13.8, 64.7 ± 12.3, and 67.8 ± 13.1 mL/min/1.73 mEven if they no longer smoke, donors with a smoking history require close observation due to increased risk of CKD development after kidney donation. A detailed pack-years smoking history should be obtained, and smoking cessation strategies should be implemented in kidney donors.

Traumatic brain injury (TBI) is a serious public health problem causing morbidity and mortality worldwide yearly. Neuroinflammation is a hallmark symptom following TBI to induce delayed secondary injury. The excessive activation of microglia, astrocytes, and other immunological mediators release pro-inflammatory cytokines causing neuronal cell death leading to neurological deficits. Currently there are no FDA-approved medications to improve cognitive function after TBI, however, the use of fatty acids has gained notoriety in recent years with the use of ω-3 polyunsaturated fatty acids (ω-3 PUFAs, i.e., DHA) providing neuroprotection against TBI-induced neuroinflammation. DHA has been extensively studied in the context of anti-inflammation, but there is a poor understanding of cerebral autoregulation in the presence of TBI. In addition, the current treatments and other potential neuroprotective compounds for TBI such as resveratrol and palmitic acid methyl ester (PAME) are discussed.

Background Although renal function recovery of living kidney donors has been reported in a number of studies, many patients show poor recovery, and the long-term prognosis of these patients has not been well studied. In this investigation we explored the long-term prognosis of renal function in patients with chronic kidney disease (CKD) at 1 year after nephrectomy. Methods Patients who underwent donor nephrectomy during the period from March 2006 to April 2014, with a follow-up creatinine study at 1 year postoperatively and more than 3 years of follow-up, were included in the study. Creatinine and estimated glomerular filtration rate (eGFR, using the Modification of Diet in Renal Disease formula) before and after surgery were studied. Age, sex, history of hypertension or diabetes, body mass index, blood pressure, complete blood count, preoperative routine serum chemistry, and urine study results were reviewed. Results Among 841 patients who had donor nephrectomy, 362 were included in the study. There were 111 patients (30.6%) with eGFR 60 mL/min/1.73 m2. Age, history of hypertension, preoperative eGFR, and eGFR at 1 year were predictive factors at univariate analysis. Multivariate analysis of these factors was studied, and age (52.5 [IQR 47–55.7] vs 47 [IQR 7–53] years, odds ratio [OR] 1.1, 95% confidence interval [CI] 1.02–1.15, P = .007), history of hypertension (16.7% vs 1.6%, OR 10.0, 95% CI 1.09–92.49, P = .042), and eGFR at 1 year (53.9 [IQR 50.3–56.0] vs 57.0 [IQR 54.2–58.4] mL/min/1.73 m2, OR 0.8, 95% CI 0.72–0.92, P = .002) remained as significant risk factors. Conclusion Of all living donors, 15.7% had CKD after >3 years of follow-up. Close observation is warranted when donors have CKD after 1 year follow-up, as 43.2% fail to recover renal function. Patients who are older, have a history of hypertension, and have low eGFR at 1-year follow-up are especially at risk.

Arterial stiffness is associated with cardiovascular disease in end-stage renal disease (ESRD) and after kidney transplantation. We examined how kidney transplantation influences brachial-ankle pulse-wave velocity (baPWV) in ESRD patients.The prospective observational study enrolled 67 patients who underwent successful kidney transplantation. Serial baPWV and biochemical parameters were measured before surgery and 6 months, 1 year, and 2 years after transplantation.baPWV prior to kidney transplantation and 6 months, 1 year, and 2 years after transplantation was 1533 ± 261 cm/s, 1417 ± 254 cm/s, 1414 ± 285 cm/s, and 1384 ± 233 cm/s, respectively. baPWV and biochemical parameters including alkaline phosphatase, intact parathyroid hormone, and 1,25 hydroxyvitamin D improved significantly at 6 months (P .05), but there were no changes between 6 months and 2 years after transplantation. The majority of patients (73%) improved, whereas the remainder showed progression of baPWV after transplantation. Sixty-three percent of all kidney transplantation patients displayed higher baPWV than the healthy control subjects at 6 months after transplant.In the majority of patients, baPWV improved soon after kidney transplantation but overall remained higher than in the generally healthy population.

A wide dynamic range CMOS image sensor is proposed, exhibiting a linear response at a low illumination level and a logarithmic response at a high illumination level. To maintain high sensitivity and to improve the dynamic range of the proposed pixel, a cascode MOSFET is integrated into the structure of the proposed pixel, along with a photogate. The applied photogate voltage reduces the sensitivity of the proposed pixel under the linear response regime, at a moderate illumination level. Under high illumination levels, the biased cascode MOSFET serves as a voltage-light-dependent active load and is responsible for logarithmic operation. The dynamic range of the proposed pixel can be improved by adjusting the sensitivity and the basis of the logarithmic response.

Background Hyperuricemia has been associated with kidney disease and remains controversial with regard to its gender-specific differences and impact in living kidney donation. Methods Between 2006 and 2015, charts of live kidney donors who underwent nephrectomy and had a minimum follow-up of 1 year were reviewed. A total of 291 donors were included and divided based on gender-specific pre-donation serum uric acid (SUA) tertiles. Renal functional outcomes included were estimated glomerular filtration rate (eGFR) at 6-month and 1-year follow-up and percentage of donors with a 1-year eGFR Results Mean SUA tertiles were 5.8 ± 1.1 mg/dL in males and 4.1 ± 1 mg/dL in females. Females in the highest tertile (SUA >4.5 mg/dL) had lower 6-month (59.9 ± 10.3 vs 66.9 ± 14.1 vs 67.3 ± 12.1; P = .018) and 1-year (60.8 ± 10.6 vs 67.6 ± 10.8 vs 67.8 ± 11.8; P = .021) eGFR and a higher percentage of donors with 1-year eGFR Conclusions Predonation SUA level is associated with the development of delayed renal recovery (GFR

A new infra-red (IR) thermography system with high spatial resolution has been installed on KSTAR and is now mainly applied to measure the outer divertor heat load profile. The first measurement results of the outer divertor heat load profiles between ELMs have been applied to characterize the inter-ELMs outer divertor heat loads in KSTAR H-mode plasmas. In particular, the power decay length (lambda(q)) of the divertor heat load profile has been determined by fitting the profile to a convolution of an exponential decay and a Gaussian function. The analysis on the power decay length shows a good agreement with the recent multi-machine.q scaling, which predicts lambda(q) of the inter-ELMs divertor heat load to be similar to 1 mm under the standard H-mode scenario in ITER. The divertor IR thermography system has also successfully measured the strike point splitting of the outer divertor heat flux during the application of resonant magnetic perturbation (RMP) fields. In addition, it has provided a clear evidence that the strike point splitting pattern depends on the RMP fields configuration. (C) 2016 Elsevier Ltd.

Heat loads deposited on the first wall by mitigated Type I ELMs are expected to be the dominant contributor to the total thermal plasma wall load of the International Thermonuclear Experimental Reactor (ITER), particularly in the upper main chamber regions during the baseline H-mode magnetic equilibrium, due to the fast radial convective heat propagation of ELM filaments before complete loss to the divertor. Specific Type I ELMing H-mode discharges have been performed with a lower single null magnetic geometry, where the outboard separatrix position is slowly (similar to 7 s) scanned over a radial distance of 7 cm, reducing the wall probe-separatrix distance to a minimum of similar to 9 cm, and allowing the ELM filament heat loss to the wall to be analyzed as a function of radial propagation distance. A fast reciprocating probe (FRP) head is separately held at fixed position toroidally close and 4.7 cm radially in front of the wall probe. This FRP monitors the ELM ion fluxes, allowing an average filament radial propagation speed, found to be independent of ELM energy, of 80-100 ms(-1) to be extracted. Radial dependence of the peak filament wall parallel heat flux is observed to be exponential, with the decay length of lambda(q,ELM) similar to 25 +/- 4 mm and with the heat flux of q(parallel to,ELM) = 0.05 MWm(-2) at the wall, corresponding to q(parallel to) similar to 7.5 MWm(-2) at the second separatrix. Along with the measured radial propagation speed and the calculated radial profile of the magnetic connection lengths across the SOL, these data could be utilized to analyze filament energy loss model for the future machines. (C) 2017 The Authors. Published by Elsevier Ltd.

Nanosize thermoelectric powder can exhibit improved performance index owing to reduction of lattice thermal conductivity. Currently, chemical or physical processes such as polyol synthesis, gas atomization, and mechanical milling are employed to prepare such powders. In this study, Te nanopowders of 5N purity were prepared using an evaporation–condensation process. The formation mechanisms for Te nanopowders and coarse crystals are discussed and correlated with condensation temperature gradient and Ar flow rate. Prepared Te powders exhibited particle sizes ranging from tens to hundreds of micrometers upon high-temperature processing to as low as tens of nanometers at low-temperature processing (room temperature). In addition, these nanopowders began to oxidize at 225 °C, and subsequently, began to evaporate at 733 °C, as observed through thermogravimetric analysis. The procedure presented here has been found to be an economical method for preparing high-purity Te nanopowders from low-purity Te feedstock.

Many techniques are available for destructive and nondestructive measurement of mechanical hardness. The ultrasonic method could be widely applicable as a nondestructive technique. Many studies have examined how changes in the mechanical hardness affect the longitudinal velocity of ultrasonic waves. This approach aims to estimate the overall velocity variations in specimens. However, proper nondestructive examination techniques are needed as effective tools for analyzing the effects of heat treatment on the surface of the specimens. Therefore, in this study, the effect on the hardness of piston rods was nondestructively measured using surface ultrasonic waves. The hardness after heat treatment was investigated at various depths in the specimens, and the velocity of the surface ultrasonic waves was measured with respect to the hardness of the piston rods. In addition, finite element method simulations were performed to confirm the behavior of the waves.

Background The optimal treatment for primary gastric diffuse large B cell lymphoma (DLBCL) is unclear. The treatment for primary gastric DLBCL is in accordance with the principle of treatment for general DLBCL. We aimed to evaluate the treatment outcomes and pattern of failure in primary gastric DLBCL. Methods Between April 2001 and November 2018, 120 patients with stage I–IV primary gastric DLBCL were retrospectively reviewed in this study. All patients had been in complete remission after receiving rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Ninety patients (75%) were treated with R-CHOP alone, and the other 30 patients (25%) underwent R-CHOP with local treatment for gastric lesions. Twelve patients (10%) underwent gastrectomy, and 18 patients (15%) received consolidation radiotherapy (RT). Results The median follow-up time was 49 (range, 5 to 197) months. The 5-year locoregional failure-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) rates were 85.6%, 86.5%, 83.4%, and 90.3%, respectively. During the follow-up, 17 patients (14.2%) experienced disease recurrence. Only 3 patients developed distant metastasis without locoregional failure (LRF). All except two cases of LRF included gastric failure. There was no LRF in patients who received R-CHOP with local treatment. On multivariate analysis, poor performance status was an independent prognostic factor for LRFS, and multiple gastric lesions influenced LRFS, DMFS, DFS, and OS. Conclusions The main pattern of initial failure is LRF, especially in the stomach in patients with primary gastric DLBCL. Gastric local treatment such as consolidation RT can effectively prevent gastric failure. Therefore, gastric local treatment should be considered for patients at high risk of LRF, such as multiple gastric lesions. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

In this study, modeling and numerical simulations has been performed to investigate performance characteristics of constant power regulator system for swash plate type axial piston pump. The commercial numerical simulation software, AMESim was applied for analyzing the dynamic behavior of constant power regulator system of swash plate axial piston pump. The validity of simulation model of constant power regulator system is verified by comparing simulation results with experiments. Also, the behavior of main components of constant power regulator system such as spool, sleeve and counterbalance piston is investigated using the results of computer simulation.

A solid-state rapid metathesis reaction was performed in a bed of sodium silicofluoride (Na2SiF6) and sodium azide (NaN3) powders diluted with sodium fluoride (NaF), to produce silicon nanoparticles. After a local ignition of Na2SiF6+4NaN3+kNaF mixture (here k is mole number of NaF), the reaction proceeded in a self-sustaining combustion mode developing high temperatures (950–1000 °C) on very short time scales (a few seconds). Silicon nanoparticles prepared by the combustion process was easily separated from the salt byproducts by simple washing with distilled water. The structural and morphological studies on the nanoparticles were carried out using X-ray diffractometer (XRD) and field emission scanning electron microscope (FESEM). The mean size of silicon particles calculated from the FESEM image was about 37.75 nm. FESEM analysis also shows that the final purified product contains a noticeable amount of silicon fibers, dendrites and blocks, along with nanoparticles. The mechanism of Si nanostructures formation is discussed and a simple model for interpretation of experimental results is proposed.

Using purified enzyme and homologous tRNA, we have investigated the order of substrate binding and product release for the human placental threonyl-tRNA synthetase by isotope exchange, initial velocity, dead-end inhibition and product inhibition studies. The kinetic patterns obtained from these studies are consistent with a unique Bi Uni Uni Bi ping-pong mechanism. The order of addition of the first two substrates ATP and threonine is random, while the release of products follows an obligatory sequence, with AMP as the last product to dissociate from the enzyme.